A hotel is accused of discriminating against homeless people after cancelling their Christmas booking.
Carl Simpson, of Raise the Roof Homeless Project, says he was "gutted" when the Royal Hotel in Hull cancelled the £1,092 booking without explanation.
The hotel later said the reason was that it had been told about damage to rooms during the group's Christmas booking at an Ibis hotel last year.
Raise the Roof says the allegations are "lies". Ibis has also denied the claim.
Raise the Roof told the BBC it booked 14 twin rooms for 28 people in twin rooms - hoping to build on the success of last year's event at the Ibis.
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It said The Royal Hotel originally accepted the booking, and that it had not attempted to conceal the guests' backgrounds.
"We told them up front they were for homeless people," Mr Simpson said. "They were fine with that."
A spokesperson for the hotel said the company had been warned by a "former project worker" not to take the booking.
"We received a call from a lady... who worked for the charity last year," the spokesperson said.
"She had rung to warn us that the group had caused serious problems at the Ibis and that she felt we should not take the booking.
"Among the issues last year were trashing of rooms, fires, theft of hotel goods and property and damage to property.
"The hotel has a number of families and tours staying at the hotel over the Christmas period which we feel would suffer if the booking was taken."
The spokesperson added that the hotel would reinstate the booking, with conditions.
The Ibis chain told the BBC it did not recognise the allegations.
In a statement, it said: "We can confirm that we welcomed a group of homeless people for two nights last Christmas booked by Raise the Roof Homeless Project, and that the organisers felt the stay was very successful.
"We don't recognise any allegations that these guests caused serious problems such as fire or theft in the hotel."
One of the homeless people who attended the Ibis hotel last year told the BBC: "It was the best Christmas present you could get, really. It's such a relief to be off the streets even for that one night."
In a Facebook post on Saturday evening, Mr Simpson said he had been hoping to repeat "the success of last Christmas" when he was able to book 28 people into an Ibis hotel for two nights.
"After the stay they were so grateful. Some left staff gifts using the very little money they had, and one asked if he could vacuum the rooms to show his appreciation.
"This means the world to homeless people. Last year we had tears of joy from someone who stood on the edge of the Humber Bridge the night before.
"We have to break the news to people that the hotel has been cancelled."
Mr Simpson said he was yet to receive a refund for the booking, and so was unable to rebook another hotel, adding: "We need a miracle."
He said he relied on donations to make the original booking and he was worried whether the number of rooms needed could be found elsewhere at an affordable price.
Since his Mr Simpson's original Facebook post, the news of the cancelled booking where it has been shared by more than 1,000 people and online fundraising for the group has received a £6,000 boost.
Speaking to the BBC's Victoria Derbyshire programme earlier, he said: "I wasn't really aware we'd reached that. That's amazing. We just need the rooms now.
"There are lots of reasons people become homeless, not just the ones they seem to be labelled with," Mr Simpson said.
"We see people from family break-ups and ex-servicemen."
The Facebook post has inspired others to try to help the homeless this Christmas.
Beckie Stewart writes: "Aren't there people willing to bring in one or two on Christmas eve? I'm sleeping over at my mum's so I'm happy to offer a room."